Bystander in ubiquitous computing

In the CatchBob! project, the location-based game I used for my PhD research, players often reported the encounter with other persons puzzled by the presence of running people with TabletPCs. The general reaction of passers-by seemed to range between ignoring the game to asking players about how to participate in trials. However, the physical environment is an overlap of lots of activities carried out by different groups and individuals, which can be conflicting. In one trial, two players tried to visit one of the campus library and the janitor forbid them to enter the building carrying out the game TabletPCs. This kind of phenomenon unfortunately undermines the engagement of players in the game, turning the experience into something less fun to achieve.
This problem has been investigated by researchers, as shown by this warning quote from one of the deliverable from the European iPerg project entitled "Designing Pervasive Games":

"Pervasive games introduce an important problem: when a game is expanded, the bystanders do not always have the means to distinguish game events from the non-game events. However, regardless of whether they know or don’t know about the game, they perhaps should have a choice pertaining the mode of attendance, i.e., they should be given chance to play, or ignore the game and appreciate it as an art artefact, or view it as a morastatement. Otherwise, the game is can lead to ethical and practical problems.
(...)
Whether unaware or aware of an ongoing game, bystanders have no intention or opportunity to participate in it or at least no opportunity to do so. Here, we probably find the most challenging effects of social expansion. Socially unexpanded games are typically completely insulated from bystanders: they are not affected by the game (even if aware of it) and they have no influence over the game."

Why do i blog this? The presence of bystanders in some pervasive games or ARG is interesting as it shows how the notion of "user" in ubiquitous computing is flawed. Unlike face-to-face (so to say) interactions with a desktop computer, ubicomp/pervasive computing/internet of things can lead to situations where people experience non-intentional participation in services/events they did not want to be engaged in.

If pervasive games can take this into account and not affect people' life, other ubicomp applications can be less careful about it. What am I thinking about? perhaps applications which tracks individuals and propose them services without any consent form the user (to be tracked or to receive services s/he does not want to receive).